The goal of this project is to develop, implement, and evaluate a community organization intervention designed to change policies and practices of major community institutions so as to reduce the accessibility of alcohol to youth age 15-20. The intervention will use the community as a vehicle for changing underage alcohol availability, to reduce youth alcohol consumption and its sequelae. The intervention, building on an explicit theoretical model of factors affecting public policy and community practices on alcohol, will engage networks of public and private organizations to enhance citizen authority, power, and capacity for effective problem solving. Major components of the intervention include: (1) detailed community analysis, identifying potential catalysts for alcohol policy change and obtaining information about community perceptions of alcohol problems, past and present community efforts on alcohol issues, and obstacles to change; (2) community education and task force formation, education of key community members on the problem of youth access and formation of adult and youth community task forces; and (3) development and implementation of a plan for community action to change community institutions, policies and practices affecting youth access to alcohol. Three major research designs will be used to evaluate intervention effects: (1) a randomized community trial with nine intervention and nine control communities, (2) a multiple time-series design nested within the randomized trial, and (3) a single-subject case study design to test the feasibility and applicability of the intervention model to American Indian communities. Major outcome indicators include accessibility of alcohol to youth from commercial outlets and noncommercial sources, patterns of alcohol use among youth, and incidence of common social and health problems associated with youth alcohol use. Data will be collected via baseline (Spring, 1992) and follow-up (Spring, 1995): (1) high school surveys, (2) telephone surveys of 18-20-year-olds, (3) telephone surveys of adults, (4) observation and alcohol purchase attempt surveys of on- and off-sale commercial alcohol outlets, and (5) archive data collection of youth alcohol problem indicators. The expected project result is a model intervention to change structural and institutional dimensions of youth access to alcohol in a community, leading to long-term behavioral changes that produce reductions in prevalence and severity of alcohol problems.